Small packet optimizations for internet-of-things applications

ABSTRACT

Certain aspects of the present disclosure relate to methods and apparatus for optimizing delivery of a small amount of mobile originated (MO) or mobile terminated (MT) data.

CLAIM OF PRIORITY UNDER 35 U.S.C. § 119

This application is a continuation of U.S. application Ser. No.16/930,059, filed Jul. 15, 2020, which is a continuation of U.S.application Ser. No. 15/874,787, filed Jan. 18, 2018, which claimsbenefit of and priority to U.S. Provisional Patent Application Ser. No.62/448,922, filed Jan. 20, 2017, assigned to the assignee hereof andhereby expressly incorporated by reference herein as if fully set forthbelow in their entireties and for all applicable purposes.

FIELD

The present disclosure relates generally to communication systems, andmore particularly, to devices, systems, methods, and apparatus foroptimizing delivery of relatively small amounts of data, such ascommonly occurs in Internet-of-Things (IoT) applications. Embodimentscan enable and provide power resource savings and enable improvedconnectivity features for device classes with lower mobility use cases(e.g., some IOT devices may have reduced mobility or may be stationary).

BACKGROUND

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power). Examples of such multiple-access technologies includeLong Term Evolution (LTE) systems, code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, orthogonal frequency divisionmultiple access (OFDMA) systems, single-carrier frequency divisionmultiple access (SC-FDMA) systems, and time division synchronous codedivision multiple access (TD-SCDMA) systems.

In some examples, a wireless multiple-access communication system mayinclude a number of base stations, each simultaneously supportingcommunication for multiple communication devices, otherwise known asuser equipment (UEs). In LTE or LTE-A network, a set of one or more basestations may define an eNodeB (eNB). In other examples (e.g., in a nextgeneration or 5G network), a wireless multiple access communicationsystem may include a number of distributed units (DUs) (e.g., edge units(EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs),transmission reception points (TRPs), etc.) in communication with anumber of central units (CUs) (e.g., central nodes (CNs), access nodecontrollers (ANCs), etc.), where a set of one or more distributed units,in communication with a central unit, may define an access node (e.g., anew radio base station (NR BS), a new radio node-B (NR NB), a networknode, 5G NB, eNB, etc.). A base station or DU may communicate with a setof UEs on downlink channels (e.g., for transmissions from a base stationor to a UE) and uplink channels (e.g., for transmissions from a UE to abase station or distributed unit).

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example of an emergingtelecommunication standard is new radio (NR), for example, 5G radioaccess. NR is a set of enhancements to the LTE mobile standardpromulgated by Third Generation Partnership Project (3GPP). It isdesigned to better support mobile broadband Internet access by improvingspectral efficiency, lowering costs, improving services, making use ofnew spectrum, and better integrating with other open standards usingOFDMA with a cyclic prefix (CP) on the downlink (DL) and on the uplink(UL) as well as support beamforming, multiple-input multiple-output(MIMO) antenna technology, and carrier aggregation.

However, as the demand for mobile broadband access continues toincrease, there exists a need for further improvements in NR technology.Preferably, these improvements should be applicable to othermulti-access technologies and the telecommunication standards thatemploy these technologies.

BRIEF SUMMARY

The systems, methods, and devices of the disclosure each have severalaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope of this disclosure as expressedby the claims which follow, some features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “Detailed Description” one will understand how thefeatures of this disclosure provide advantages that include improvedcommunications between access points and stations in a wireless network.

Certain aspects of the present disclosure generally relate to methodsand apparatus for optimizing delivery of relatively small amounts ofdata. Embodiments can include deployments where IoT applications/systemsare based on devices with little to no mobility or capable of operatingin scenarios with limited mobility. Such arrangements enable deploymentsand scenarios with reduced overhead as further discussed below.

Certain aspects of the present disclosure provide a method for wirelesscommunication by a base station. The method generally includes receivinga paging indication and at least an indication of a limited amount ofdata targeted for a user equipment (UE) that is not in a connected statewith the base station, transmitting a paging message to the UE with atleast one of the data or an indication of the data, and monitoring for aphysical random access channel (PRACH) transmission from the UE as anacknowledgment of receipt of the data

Certain aspects of the present disclosure provide a method for wirelesscommunication by a base station. The method generally includes receivinga paging indication and at least an indication of a limited amount ofdata targeted for a user equipment (UE) that is not in a connected statewith the base station, transmitting a paging message to the UE with theindication of the data, and transmitting the data after the pagingmessage

Certain aspects of the present disclosure provide a method for wirelesscommunication by a user equipment (UE). The method generally includesreceiving from a base station, while not in a connected state, a pagingmessage and at least an indication of a limited amount of data targetedfor the UE, receiving the data in at least one of the paging message ora subsequent message, and transmitting a physical random access channel(PRACH) to the base station as an acknowledgment of receipt of the data

Certain aspects of the present disclosure provide a method for wirelesscommunication by a user equipment (UE). The method generally includesreceiving from a base station, while not in a connected state, a pagingmessage and at least an indication of a limited amount of data targetedfor the UE and receiving the data in a subsequent message after thepaging message

Certain aspects of the present disclosure provide a method for wirelesscommunication by a user equipment (UE). The method generally includesdetermining a set of resources for connectionless delivery of a limitedamount of data to a base station, based at least in part on an amount ofthe data the UE has to send and transmitting to the base station, whilenot in a connected state, the limited amount of data using thedetermined set of resources

Certain aspects of the present disclosure provide a method for wirelesscommunication by a base station. The method generally includesdetermining a set of resources for connectionless delivery of a limitedamount of data from a user equipment (UE), based at least in part on anamount of the data the UE has to send and receiving from the UE, whilethe UE is not in a connected state, the limited amount of data using thedetermined set of resources

Aspects generally include methods, apparatus, systems, computer readablemediums, and processing systems, as substantially described herein withreference to and as illustrated by the accompanying drawings.

Other aspects, features, and embodiments of the technology will becomeapparent to those of ordinary skill in the art, upon reviewing thefollowing description of specific, exemplary embodiments in conjunctionwith the accompanying figures. While features of the technologydiscussed below may be described relative to certain embodiments andfigures below, all embodiments can include one or more of theadvantageous features discussed. While one or more embodiments may bediscussed as having certain advantageous features, one or more of suchfeatures may also be used in accordance with the various embodimentsdiscussed. In similar fashion, while exemplary embodiments may bediscussed below as device, system, or method embodiments it should beunderstood that such exemplary embodiments can be implemented in varyingshapes, sizes, layouts, arrangements, circuits, devices, systems, andmethods.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only certain typicalaspects of this disclosure and are therefore not to be consideredlimiting of its scope, for the description may admit to other equallyeffective aspects.

FIG. 1 is a block diagram conceptually illustrating an exampletelecommunications system, in accordance with certain aspects of thepresent disclosure.

FIG. 2 is a block diagram illustrating an example logical architectureof a distributed RAN, in accordance with certain aspects of the presentdisclosure.

FIG. 3 is a diagram illustrating an example physical architecture of adistributed RAN, in accordance with certain aspects of the presentdisclosure.

FIG. 4 is a block diagram conceptually illustrating a design of anexample BS and user equipment (UE), in accordance with certain aspectsof the present disclosure.

FIG. 5 is a diagram showing examples for implementing a communicationprotocol stack, in accordance with certain aspects of the presentdisclosure.

FIG. 6 illustrates an example of a DL-centric subframe, in accordancewith certain aspects of the present disclosure.

FIG. 7 illustrates an example of an UL-centric subframe, in accordancewith certain aspects of the present disclosure.

FIG. 8 illustrates example operations that may be performed by a basestation to help optimize delivery of small amount of mobile terminated(MT) data, in accordance with certain aspects of the present disclosure.

FIG. 9 illustrates example operations that may be performed by a userequipment to help optimize delivery of small amount of MT data, inaccordance with certain aspects of the present disclosure.

FIG. 10 illustrates example operations that may be performed by anetwork entity to help optimize delivery of small amount of MT data, inaccordance with certain aspects of the present disclosure.

FIG. 11 is an example call flow diagram for delivering a small amount ofMT data in a paging message, in accordance with certain aspects of thepresent disclosure.

FIG. 12 illustrates example code for formation of a paging message, inaccordance with certain aspects of the present disclosure.

FIGS. 13-15 are example call flow diagrams for delivering a small amountof MT data following a paging message, in accordance with certainaspects of the present disclosure.

FIGS. 16 and 17 illustrate example code for formation of a pagingmessage and downlink data message, in accordance with certain aspects ofthe present disclosure.

FIG. 18 illustrates example operations that may be performed by a userequipment to help optimize delivery of small amount of mobile originated(MO) data, in accordance with certain aspects of the present disclosure.

FIG. 19 illustrates example operations that may be performed by a basestation to help optimize delivery of small amount of MO data, inaccordance with certain aspects of the present disclosure.

FIG. 20 is an example call flow diagram for delivering a small amount ofMO data, in accordance with certain aspects of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in one aspectmay be beneficially utilized on other aspects without specificrecitation.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatus, methods, processingsystems, and computer readable mediums for new radio (NR) (new radioaccess technology or 5G technology).

NR may support various wireless communication services, such as Enhancedmobile broadband (eMBB) targeting wide bandwidth (e.g. 80 MHz beyond),millimeter wave (mmW) targeting high carrier frequency (e.g. 60 GHz),massive MTC (mMTC) targeting non-backward compatible MTC techniques,and/or mission critical targeting ultra-reliable low latencycommunications (URLLC). These services may include latency andreliability requirements. These services may also have differenttransmission time intervals (TTI) to meet respective quality of service(QoS) requirements. In addition, these services may co-exist in the samesubframe.

Aspects of the present disclosure relate to optimizing delivery of arelatively small amount of data, for example, by significantly reducingthe amount of signaling overhead required for such delivery.

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in some other examples. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim. The word “exemplary”is used herein to mean “serving as an example, instance, orillustration.” Any aspect described herein as “exemplary” is notnecessarily to be construed as preferred or advantageous over otheraspects.

The techniques described herein may be used for various wirelesscommunication networks such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA andother networks. The terms “network” and “system” are often usedinterchangeably. A CDMA network may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. cdma2000 coversIS-2000, IS-95 and IS-856 standards. A TDMA network may implement aradio technology such as Global System for Mobile Communications (GSM).An OFDMA network may implement a radio technology such as NR (e.g. 5GRA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA andE-UTRA are part of Universal Mobile Telecommunication System (UMTS). NRis an emerging wireless communications technology under development inconjunction with the 5G Technology Forum (5GTF). 3GPP Long TermEvolution (LTE) and LTE-Advanced (LTE-A) are releases of UMTS that useE-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described indocuments from an organization named “3rd Generation PartnershipProject” (3GPP). cdma2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2). Thetechniques described herein may be used for the wireless networks andradio technologies mentioned above as well as other wireless networksand radio technologies. For clarity, while aspects may be describedherein using terminology commonly associated with 3G and/or 4G wirelesstechnologies, aspects of the present disclosure can be applied in othergeneration-based communication systems, such as 5G and later, includingNR technologies.

While aspects and embodiments are described in this application byillustration to some examples, those skilled in the art will understandthat additional implementations and use cases may come about in manydifferent arrangements and scenarios. Innovations described herein maybe implemented across many differing platform types, devices, systems,shapes, sizes, packaging arrangements. For example, embodiments and/oruses may come about via integrated chip embodiments and othernon-module-component based devices (e.g., end-user devices, vehicles,communication devices, computing devices, industrial equipment,retail/purchasing devices, medical devices, AI-enabled devices, etc.).While some examples may or may not be specifically directed to use casesor applications, a wide assortment of applicability of describedinnovations may occur. Implementations may range a spectrum fromchip-level or modular components to non-modular, non-chip-levelimplementations and further to aggregate, distributed, or OEM devices orsystems incorporating one or more aspects of the described innovations.In some practical settings, devices incorporating described aspects andfeatures may also necessarily include additional components and featuresfor implementation and practice of claimed and described embodiments.For example, transmission and reception of wireless signals necessarilyincludes a number of components for analog and digital purposes (e.g.,hardware components including antenna, RF-chains, power amplifiers,modulators, buffer, processor(s), interleaver, adders/summers, etc.). Itis intended that innovations described herein may be practiced in a widevariety of devices, chip-level components, systems, distributedarrangements, end-user devices, etc. of varying sizes, shapes, andconstitution.

Example Wireless Communications System

FIG. 1 illustrates an example wireless network 100, such as a new radio(NR) or 5G network, in which aspects of the present disclosure may beperformed, for example, for enabling connectivity sessions and internetprotocol (IP) establishment, as described in greater detail below.

As illustrated in FIG. 1 , the wireless network 100 may include a numberof BSs 110 and other network entities. A BS may be a station thatcommunicates with UEs. Each BS 110 may provide communication coveragefor a particular geographic area. In 3GPP, the term “cell” can refer toa coverage area of a Node B and/or a Node B subsystem serving thiscoverage area, depending on the context in which the term is used. In NRsystems, the term “cell” and eNB, Node B, 5G NB, AP, NR BS, NR BS, orTRP may be interchangeable. In some examples, a cell may not necessarilybe stationary, and the geographic area of the cell may move according tothe location of a mobile base station. In some examples, the basestations may be interconnected to one another and/or to one or moreother base stations or network nodes (not shown) in the wireless network100 through various types of backhaul interfaces such as a directphysical connection, a virtual network, or the like using any suitabletransport network.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular radioaccess technology (RAT) and may operate on one or more frequencies. ARAT may also be referred to as a radio technology, an air interface,etc. A frequency may also be referred to as a carrier, a frequencychannel, etc. Each frequency may support a single RAT in a givengeographic area in order to avoid interference between wireless networksof different RATs. In some cases, NR or 5G RAT networks may be deployed.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or other types of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a Closed Subscriber Group (CSG), UEs for users in the home,etc.). A BS for a macro cell may be referred to as a macro BS. A BS fora pico cell may be referred to as a pico BS. A BS for a femto cell maybe referred to as a femto BS or a home BS. In the example shown in FIG.1 , the BSs 110 a, 110 b and 110 c may be macro BSs for the macro cells102 a, 102 b and 102 c, respectively. The BS 110 x may be a pico BS fora pico cell 102 x. The BSs 110 y and 110 z may be femto BS for the femtocells 102 y and 102 z, respectively. A BS may support one or multiple(e.g., three) cells.

The wireless network 100 may also include relay stations. A relaystation is a station that receives a transmission of data and/or otherinformation from an upstream station (e.g., a BS or a UE) and sends atransmission of the data and/or other information to a downstreamstation (e.g., a UE or a BS). A relay station may also be a UE thatrelays transmissions for other UEs. In the example shown in FIG. 1 , arelay station 110 r may communicate with the BS 110 a and a UE 120 r inorder to facilitate communication between the BS 110 a and the UE 120 r.A relay station may also be referred to as a relay BS, a relay, etc.

The wireless network 100 may be a heterogeneous network that includesBSs of different types, e.g., macro BS, pico BS, femto BS, relays, etc.These different types of BSs may have different transmit power levels,different coverage areas, and different impact on interference in thewireless network 100. For example, macro BS may have a high transmitpower level (e.g., 20 Watts) whereas pico BS, femto BS, and relays mayhave a lower transmit power level (e.g., 1 Watt).

The wireless network 100 may support synchronous or asynchronousoperation. For synchronous operation, the BSs may have similar frametiming, and transmissions from different BSs may be approximatelyaligned in time. For asynchronous operation, the BSs may have differentframe timing, and transmissions from different BSs may not be aligned intime. The techniques described herein may be used for both synchronousand asynchronous operation.

A network controller 130 may communicate with a set of BSs and providecoordination and control for these BSs. The network controller 130 maycommunicate with the BSs 110 via a backhaul. The BSs 110 may alsocommunicate with one another, e.g., directly or indirectly via wirelessor wireline backhaul.

The UEs 120 (e.g., 120 x, 120 y, etc.) may be dispersed throughout thewireless network 100, and each UE may be stationary or mobile. A UE mayalso be referred to as a mobile station, a terminal, an access terminal,a subscriber unit, a station, a Customer Premises Equipment (CPE), acellular phone, a smart phone, a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, a medical device or medical equipment, a biometricsensor/device, a wearable device such as a smart watch, smart clothing,smart glasses, a smart wrist band, smart jewelry (e.g., a smart ring, asmart bracelet, etc.), an entertainment device (e.g., a music device, avideo device, a satellite radio, etc.), a vehicular component or sensor,a smart meter/sensor, industrial manufacturing equipment, a globalpositioning system device, or any other suitable device that isconfigured to communicate via a wireless or wired medium. Some UEs maybe considered evolved or machine-type communication (MTC) devices orevolved MTC (eMTC) devices. MTC and eMTC UEs include, for example,robots, drones, remote devices, sensors, meters, monitors, locationtags, etc., that may communicate with a BS, another device (e.g., remotedevice), or some other entity. A wireless node may provide, for example,connectivity for or to a network (e.g., a wide area network such asInternet or a cellular network) via a wired or wireless communicationlink. Some UEs may be considered Internet-of-Things (IoT) devices.

In FIG. 1 , a solid line with double arrows indicates desiredtransmissions between a UE and a serving BS, which is a BS designated toserve the UE on the downlink and/or uplink. A dashed line with doublearrows indicates interfering transmissions between a UE and a BS.

Certain wireless networks (e.g., LTE) utilize orthogonal frequencydivision multiplexing (OFDM) on the downlink and single-carrierfrequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDMpartition the system bandwidth into multiple (K) orthogonal subcarriers,which are also commonly referred to as tones, bins, etc. Each subcarriermay be modulated with data. In general, modulation symbols are sent inthe frequency domain with OFDM and in the time domain with SC-FDM. Thespacing between adjacent subcarriers may be fixed, and the total numberof subcarriers (K) may be dependent on the system bandwidth. Forexample, the spacing of the subcarriers may be 15 kHz and the minimumresource allocation (called a ‘resource block’) may be 12 subcarriers(or 180 kHz). Consequently, the nominal FFT size may be equal to 128,256, 512, 1024 or 2048 for system bandwidth of 1.25, 2.5, 5, 10 or 20megahertz (MHz), respectively. The system bandwidth may also bepartitioned into subbands. For example, a subband may cover 1.08 MHz(i.e., 6 resource blocks), and there may be 1, 2, 4, 8 or 16 subbandsfor system bandwidth of 1.25, 2.5, 5, 10 or 20 MHz, respectively.

While aspects of the examples described herein may be associated withLTE technologies, aspects of the present disclosure may be applicablewith other wireless communications systems, such as NR. NR may utilizeOFDM with a CP on the uplink and downlink and include support forhalf-duplex operation using time division duplex (TDD). A singlecomponent carrier bandwidth of 100 MHz may be supported. NR resourceblocks may span 12 sub-carriers with a sub-carrier bandwidth of 75 kHzover a 0.1 ms duration. Each radio frame may consist of 50 subframeswith a length of 10 ms. Consequently, each subframe may have a length of0.2 ms. Each subframe may indicate a link direction (i.e., DL or UL) fordata transmission and the link direction for each subframe may bedynamically switched. Each subframe may include DL/UL data as well asDL/UL control data. UL and DL subframes for NR may be as described inmore detail below with respect to FIGS. 6 and 7 . Beamforming may besupported and beam direction may be dynamically configured. MIMOtransmissions with precoding may also be supported. MIMO configurationsin the DL may support up to 8 transmit antennas with multi-layer DLtransmissions up to 8 streams and up to 2 streams per UE. Multi-layertransmissions with up to 2 streams per UE may be supported. Aggregationof multiple cells may be supported with up to 8 serving cells.Alternatively, NR may support a different air interface, other than anOFDM-based. NR networks may include entities such CUs and/or DUs.

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station) allocates resources forcommunication among some or all devices and equipment within its servicearea or cell. Within the present disclosure, as discussed further below,the scheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more subordinateentities. That is, for scheduled communication, subordinate entitiesutilize resources allocated by the scheduling entity. Base stations arenot the only entities that may function as a scheduling entity. That is,in some examples, a UE may function as a scheduling entity, schedulingresources for one or more subordinate entities (e.g., one or more otherUEs). In this example, the UE is functioning as a scheduling entity, andother UEs utilize resources scheduled by the UE for wirelesscommunication. A UE may function as a scheduling entity in apeer-to-peer (P2P) network, and/or in a mesh network. In a mesh networkexample, UEs may optionally communicate directly with one another inaddition to communicating with the scheduling entity.

Thus, in a wireless communication network with a scheduled access totime-frequency resources and having a cellular configuration, a P2Pconfiguration, and a mesh configuration, a scheduling entity and one ormore subordinate entities may communicate utilizing the scheduledresources.

As noted above, a RAN may include a CU and DUs. A NR BS (e.g., eNB, 5GNode B, Node B, transmission reception point (TRP), access point (AP))may correspond to one or multiple BSs. NR cells can be configured asaccess cell (ACells) or data only cells (DCells). For example, the RAN(e.g., a central unit or distributed unit) can configure the cells.DCells may be cells used for carrier aggregation or dual connectivity,but not used for initial access, cell selection/reselection, orhandover. In some cases DCells may not transmit synchronizationsignals—in some case cases DCells may transmit SS. NR BSs may transmitdownlink signals to UEs indicating the cell type. Based on the cell typeindication, the UE may communicate with the NR BS. For example, the UEmay determine NR BSs to consider for cell selection, access, handover,and/or measurement based on the indicated cell type.

FIG. 2 illustrates an example logical architecture of a distributedradio access network (RAN) 200, which may be implemented in the wirelesscommunication system illustrated in FIG. 1 . A 5G access node 206 mayinclude an access node controller (ANC) 202. The ANC may be a centralunit (CU) of the distributed RAN 200. The backhaul interface to the nextgeneration core network (NG-CN) 204 may terminate at the ANC. Thebackhaul interface to neighboring next generation access nodes (NG-ANs)may terminate at the ANC. The ANC may include one or more TRPs 208(which may also be referred to as BSs, NR BSs, Node Bs, 5G NB s, APs, orsome other term). As described above, a TRP may be used interchangeablywith “cell.”

The TRPs 208 may be a DU. The TRPs may be connected to one ANC (ANC 202)or more than one ANC (not illustrated). For example, for RAN sharing,radio as a service (RaaS), and service specific AND deployments, the TRPmay be connected to more than one ANC. A TRP may include one or moreantenna ports. The TRPs may be configured to individually (e.g., dynamicselection) or jointly (e.g., joint transmission) serve traffic to a UE.

The local architecture 200 may be used to illustrate fronthauldefinition. The architecture may be defined that support fronthaulingsolutions across different deployment types. For example, thearchitecture may be based on transmit network capabilities (e.g.,bandwidth, latency, and/or jitter).

The architecture may share features and/or components with LTE.According to aspects, the next generation AN (NG-AN) 210 may supportdual connectivity with NR. The NG-AN may share a common fronthaul forLTE and NR.

The architecture may enable cooperation between and among TRPs 208. Forexample, cooperation may be preset within a TRP and/or across TRPs viathe ANC 202. According to aspects, no inter-TRP interface may beneeded/present.

According to aspects, a dynamic configuration of split logical functionsmay be present within the architecture 200. As will be described in moredetail with reference to FIG. 5 , the Radio Resource Control (RRC)layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control(RLC) layer, Medium Access Control (MAC) layer, and a Physical (PHY)layers may be adaptably placed at the DU or CU (e.g., TRP or ANC,respectively). According to certain aspects, a BS may include a centralunit (CU) (e.g., ANC 202) and/or one or more distributed units (e.g.,one or more TRPs 208).

FIG. 3 illustrates an example physical architecture of a distributed RAN300, according to aspects of the present disclosure. A centralized corenetwork unit (C-CU) 302 may host core network functions. The C-CU may becentrally deployed. C-CU functionality may be offloaded (e.g., toadvanced wireless services (AWS)), in an effort to handle peak capacity.

A centralized RAN unit (C-RU) 304 may host one or more ANC functions.Optionally, the C-RU may host core network functions locally. The C-RUmay have distributed deployment. The C-RU may be closer to the networkedge.

A DU 306 may host one or more TRPs (edge node (EN), an edge unit (EU), aradio head (RH), a smart radio head (SRH), or the like). The DU may belocated at edges of the network with radio frequency (RF) functionality.

FIG. 4 illustrates example components of the BS 110 and UE 120illustrated in FIG. 1 , which may be used to implement aspects of thepresent disclosure. As described above, the BS may include a TRP. One ormore components of the BS 110 and UE 120 may be used to practice aspectsof the present disclosure. For example, antennas 452, Tx/Rx 222,processors 466, 458, 464, and/or controller/processor 480 of the UE 120and/or antennas 434, processors 460, 420, 438, and/orcontroller/processor 440 of the BS 110 may be used to perform theoperations described herein and illustrated with reference to thefigures.

FIG. 4 shows a block diagram of a design of a BS 110 and a UE 120, whichmay be one of the BSs and one of the UEs in FIG. 1 . For a restrictedassociation scenario, the base station 110 may be the macro BS 110 c inFIG. 1 , and the UE 120 may be the UE 120 y. The base station 110 mayalso be a base station of some other type. The base station 110 may beequipped with antennas 434 a through 434 t, and the UE 120 may beequipped with antennas 452 a through 452 r.

At the base station 110, a transmit processor 420 may receive data froma data source 412 and control information from a controller/processor440. The control information may be for the Physical Broadcast Channel(PBCH), Physical Control Format Indicator Channel (PCFICH), PhysicalHybrid ARQ Indicator Channel (PHICH), Physical Downlink Control Channel(PDCCH), etc. The data may be for the Physical Downlink Shared Channel(PDSCH), etc. The processor 420 may process (e.g., encode and symbolmap) the data and control information to obtain data symbols and controlsymbols, respectively. The processor 420 may also generate referencesymbols, e.g., for the PSS, SSS, and cell-specific reference signal. Atransmit (TX) multiple-input multiple-output (MIMO) processor 430 mayperform spatial processing (e.g., precoding) on the data symbols, thecontrol symbols, and/or the reference symbols, if applicable, and mayprovide output symbol streams to the modulators (MODs) 432 a through 432t. For example, the TX MIMO processor 430 may perform certain aspectsdescribed herein for RS multiplexing. Each modulator 432 may process arespective output symbol stream (e.g., for OFDM, etc.) to obtain anoutput sample stream. Each modulator 432 may further process (e.g.,convert to analog, amplify, filter, and upconvert) the output samplestream to obtain a downlink signal. Downlink signals from modulators 432a through 432 t may be transmitted via the antennas 434 a through 434 t,respectively.

At the UE 120, the antennas 452 a through 452 r may receive the downlinksignals from the base station 110 and may provide received signals tothe demodulators (DEMODs) 454 a through 454 r, respectively. Eachdemodulator 454 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 454 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 456 may obtainreceived symbols from all the demodulators 454 a through 454 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. For example, MIMO detector 456 may provide detected RStransmitted using techniques described herein. A receive processor 458may process (e.g., demodulate, deinterleave, and decode) the detectedsymbols, provide decoded data for the UE 120 to a data sink 460, andprovide decoded control information to a controller/processor 480.

On the uplink, at the UE 120, a transmit processor 464 may receive andprocess data (e.g., for the Physical Uplink Shared Channel (PUSCH)) froma data source 462 and control information (e.g., for the Physical UplinkControl Channel (PUCCH) from the controller/processor 480. The transmitprocessor 464 may also generate reference symbols for a referencesignal. The symbols from the transmit processor 464 may be precoded by aTX MIMO processor 466 if applicable, further processed by thedemodulators 454 a through 454 r (e.g., for SC-FDM, etc.), andtransmitted to the base station 110. At the BS 110, the uplink signalsfrom the UE 120 may be received by the antennas 434, processed by themodulators 432, detected by a MIMO detector 436 if applicable, andfurther processed by a receive processor 438 to obtain decoded data andcontrol information sent by the UE 120. The receive processor 438 mayprovide the decoded data to a data sink 439 and the decoded controlinformation to the controller/processor 440.

The controllers/processors 440 and 480 may direct the operation at thebase station 110 and the UE 120, respectively. The processor 440 and/orother processors and modules at the base station 110 may perform ordirect, e.g., the execution of the functional blocks illustrated in thefigures, and/or other processes for the techniques described herein. Theprocessor 480 and/or other processors and modules at the UE 120 may alsoperform or direct processes for the techniques described herein. Thememories 442 and 482 may store data and program codes for the BS 110 andthe UE 120, respectively. A scheduler 444 may schedule UEs for datatransmission on the downlink and/or uplink.

FIG. 5 illustrates a diagram 500 showing examples for implementing acommunications protocol stack, according to aspects of the presentdisclosure. The illustrated communications protocol stacks may beimplemented by devices operating in a in a 5G system (e.g., a systemthat supports uplink-based mobility). Diagram 500 illustrates acommunications protocol stack including a Radio Resource Control (RRC)layer 510, a Packet Data Convergence Protocol (PDCP) layer 515, a RadioLink Control (RLC) layer 520, a Medium Access Control (MAC) layer 525,and a Physical (PHY) layer 530. In various examples the layers of aprotocol stack may be implemented as separate modules of software,portions of a processor or ASIC, portions of non-collocated devicesconnected by a communications link, or various combinations thereof.Collocated and non-collocated implementations may be used, for example,in a protocol stack for a network access device (e.g., ANs, CUs, and/orDUs) or a UE.

A first option 505-a shows a split implementation of a protocol stack,in which implementation of the protocol stack is split between acentralized network access device (e.g., an ANC 202 in FIG. 2 ) anddistributed network access device (e.g., DU 208 in FIG. 2 ). In thefirst option 505-a, an RRC layer 510 and a PDCP layer 515 may beimplemented by the central unit, and an RLC layer 520, a MAC layer 525,and a PHY layer 530 may be implemented by the DU. In various examplesthe CU and the DU may be collocated or non-collocated. The first option505-a may be useful in a macro cell, micro cell, or pico celldeployment.

A second option 505-b shows a unified implementation of a protocolstack, in which the protocol stack is implemented in a single networkaccess device (e.g., access node (AN), new radio base station (NR BS), anew radio Node-B (NR NB), a network node (NN), or the like.). In thesecond option, the RRC layer 510, the PDCP layer 515, the RLC layer 520,the MAC layer 525, and the PHY layer 530 may each be implemented by theAN. The second option 505-b may be useful in a femto cell deployment.

Regardless of whether a network access device implements part or all ofa protocol stack, a UE may implement an entire protocol stack (e.g., theRRC layer 510, the PDCP layer 515, the RLC layer 520, the MAC layer 525,and the PHY layer 530).

FIG. 6 is a diagram 600 showing an example of a DL-centric subframe. TheDL-centric subframe may include a control portion 602. The controlportion 602 may exist in the initial or beginning portion of theDL-centric subframe. The control portion 602 may include variousscheduling information and/or control information corresponding tovarious portions of the DL-centric subframe. In some configurations, thecontrol portion 602 may be a physical DL control channel (PDCCH), asindicated in FIG. 6 . The DL-centric subframe may also include a DL dataportion 604. The DL data portion 604 may sometimes be referred to as thepayload of the DL-centric subframe. The DL data portion 604 may includethe communication resources utilized to communicate DL data from thescheduling entity (e.g., UE or BS) to the subordinate entity (e.g., UE).In some configurations, the DL data portion 604 may be a physical DLshared channel (PDSCH).

The DL-centric subframe may also include a common UL portion 606. Thecommon UL portion 606 may sometimes be referred to as an UL burst, acommon UL burst, and/or various other suitable terms. The common ULportion 606 may include feedback information corresponding to variousother portions of the DL-centric subframe. For example, the common ULportion 606 may include feedback information corresponding to thecontrol portion 602. Non-limiting examples of feedback information mayinclude an ACK signal, a NACK signal, a HARQ indicator, and/or variousother suitable types of information. The common UL portion 606 mayinclude additional or alternative information, such as informationpertaining to random access channel (RACH) procedures, schedulingrequests (SRs), and various other suitable types of information. Asillustrated in FIG. 6 , the end of the DL data portion 604 may beseparated in time from the beginning of the common UL portion 606. Thistime separation may sometimes be referred to as a gap, a guard period, aguard interval, and/or various other suitable terms. This separationprovides time for the switch-over from DL communication (e.g., receptionoperation by the subordinate entity (e.g., UE)) to UL communication(e.g., transmission by the subordinate entity (e.g., UE)). One ofordinary skill in the art will understand that the foregoing is merelyone example of a DL-centric subframe and alternative structures havingsimilar features may exist without necessarily deviating from theaspects described herein.

FIG. 7 is a diagram 700 showing an example of an UL-centric subframe.The UL-centric subframe may include a control portion 702. The controlportion 702 may exist in the initial or beginning portion of theUL-centric subframe. The control portion 702 in FIG. 7 may be similar tothe control portion described above with reference to FIG. 6 . TheUL-centric subframe may also include an UL data portion 704. The UL dataportion 704 may sometimes be referred to as the payload of theUL-centric subframe. The UL portion may refer to the communicationresources utilized to communicate UL data from the subordinate entity(e.g., UE) to the scheduling entity (e.g., UE or BS). In someconfigurations, the control portion 702 may be a physical DL controlchannel (PDCCH).

As illustrated in FIG. 7 , the end of the control portion 702 may beseparated in time from the beginning of the UL data portion 704. Thistime separation may sometimes be referred to as a gap, guard period,guard interval, and/or various other suitable terms. This separationprovides time for the switch-over from DL communication (e.g., receptionoperation by the scheduling entity) to UL communication (e.g.,transmission by the scheduling entity). The UL-centric subframe may alsoinclude a common UL portion 706. The common UL portion 706 in FIG. 7 maybe similar to the common UL portion 706 described above with referenceto FIG. 7 . The common UL portion 706 may additional or alternativeinclude information pertaining to channel quality indicator (CQI),sounding reference signals (SRSs), and various other suitable types ofinformation. One of ordinary skill in the art will understand that theforegoing is merely one example of an UL-centric subframe andalternative structures having similar features may exist withoutnecessarily deviating from the aspects described herein.

In some circumstances, two or more subordinate entities (e.g., UEs) maycommunicate with each other using sidelink signals. Real-worldapplications of such sidelink communications may include public safety,proximity services, UE-to-network relaying, vehicle-to-vehicle (V2V)communications, Internet of Everything (IoE) communications, IoTcommunications, mission-critical mesh, and/or various other suitableapplications. Generally, a sidelink signal may refer to a signalcommunicated from one subordinate entity (e.g., UE1) to anothersubordinate entity (e.g., UE2) without relaying that communicationthrough the scheduling entity (e.g., UE or BS), even though thescheduling entity may be utilized for scheduling and/or controlpurposes. In some examples, the sidelink signals may be communicatedusing a licensed spectrum (unlike wireless local area networks, whichtypically use an unlicensed spectrum).

A UE may operate in various radio resource configurations, including aconfiguration associated with transmitting pilots using a dedicated setof resources (e.g., a radio resource control (RRC) dedicated state,etc.) or a configuration associated with transmitting pilots using acommon set of resources (e.g., an RRC common state, etc.). Whenoperating in the RRC dedicated state, the UE may select a dedicated setof resources for transmitting a pilot signal to a network. Whenoperating in the RRC common state, the UE may select a common set ofresources for transmitting a pilot signal to the network. In eithercase, a pilot signal transmitted by the UE may be received by one ormore network access devices, such as an AN, or a DU, or portionsthereof. Each receiving network access device may be configured toreceive and measure pilot signals transmitted on the common set ofresources, and also receive and measure pilot signals transmitted ondedicated sets of resources allocated to the UEs for which the networkaccess device is a member of a monitoring set of network access devicesfor the UE. One or more of the receiving network access devices, or a CUto which receiving network access device(s) transmit the measurements ofthe pilot signals, may use the measurements to identify serving cellsfor the UEs, or to initiate a change of serving cell for one or more ofthe UEs.

Example Optimizations for Small Packet Delivery for Internet-of-ThingsApplications

There are various IoT applications that involve an exchange ofrelatively small amounts of data. For example, metering and alarmapplications typically involve a small amount of mobile originated (MO)data, while various queries, notifications of updates, actionablecommands (e.g., enabling actuators), and the like involve a small amountof mobile terminated (MT) data.

Unfortunately, establishing a connection between a mobile device andnetwork involves a large overhead (relative to the small amount ofdata). For example, for MT data, a device must first be paged and atotal of 6 message are exchanged (Paging, msg1, msg2, msg3, msg4, andmsg5). For MO data, the mobile must perform a RACH procedure so a totalof 4 messages are exchanged (msg1, msg2, msg3, and msg4).

Aspects of the present disclosure may take advantage of the highprobability that, in many applications that involve small packetdelivery, the IoT devices involved may be relatively stationary (e.g.,with little or no mobility). As a result, the network may know with highlikelihood the cell in which the UE is camping.

Aspects of the present disclosure may help optimize small data delivery,in such cases, by encapsulating downlink data in a packet (e.g., a NASPDU) and include it in the paging message or a message following thepaging message. As will be described in greater detail below, anacknowledgement of the small amount of downlink (MT) data may betransmitted using PRACH over the radio interface

FIG. 8 illustrates example operations 800 that may be performed by abase station to help optimize delivery of small amount of mobileterminated (MT) data, in accordance with certain aspects of the presentdisclosure.

Operations 800 begin, at 802, by receiving a paging indication and atleast an indication of a limited amount of data targeted for a userequipment (UE) that is not in a connected state with the base station.At 804, the base station transmits a paging message to the UE with atleast one of the data or an indication of the data.

In some cases, if the data is not included in the paging message, thedata may be transmitted after the paging message, at 806. In some cases,at 808, the base station may monitor for a physical random accesschannel (PRACH) transmission from the UE as an acknowledgment of receiptof the data

FIG. 9 illustrates example operations 900 that may be performed by auser equipment to help optimize delivery of small amount of MT data, inaccordance with certain aspects of the present disclosure. Operations900 may be considered complementary to operations 800, for example,performed by a UE to receive a small amount of data delivered inaccordance with operations 800.

Operations 900 begin, at 902, by receiving from a base station, whilenot in a connected state, a paging message and at least an indication ofa limited amount of data targeted for the UE. At 904, the UE receivesthe data in at least one of the paging message or a subsequent message.

In some cases, if the data is not included in the paging message, the UEmay receive the data after the paging message, at 906. In some cases, at908, the UE may transmit a physical random access channel (PRACH)transmission as an acknowledgment of receipt of the data

FIG. 10 illustrates example operations 1000 that may be performed by anetwork entity (e.g., an MME/S-GW) to help optimize delivery of smallamount of MT data to a UE via a base station, in accordance with certainaspects of the present disclosure.

Operations 1000 begin, at 1002, by deciding whether to transmit data toa UE using a connectionless data delivery mechanism involving paging,based on at least one of capability of the UE or an amount of data to bedelivered to the UE. At 1004, the network entity delivers the data tothe UE in accordance with the decision.

FIG. 11 is an example call flow diagram for delivering a small amount ofMT data in a paging message, in accordance with certain aspects of thepresent disclosure. For example, the eNB, UE, and MME (and/or S-GW) mayperform operations described above with reference to FIGS. 8, 9, and 10, respectively.

As illustrated, at step (1), the S-GW receives DL data. The S-GW mayfirst need to know that the UE (for which the DL data is directed)supports small data over paging. Both the UE, eNB and MME would need tosupport such deliver and the support (and monitoring) of this featuremay be negotiated when the UE registers with the network.

Even if supported, the S-GW may need to determine whether to useconnectionless small data delivery or establish a connection. In somecases, such determination may be based on an explicit configuration(e.g., having an API to let the application layer choose the type ofmessage—connection or small data). As another option, a timer may beused, such that if no new messages are received within a time period,connectionless small data delivery is used (as the overhead ofestablishing a connection is not warranted). On the other hand, if moremessages are received, the overhead may be warranted and a normalprocedure may be used. In some cases, whether to use small data deliveryor establish a connection may be decided based on the size of data.

In any cases, as illustrated at step (2), the S-GW may send a “smalldata transfer request” to the MME with the data to transmit. The MME maybuffer this data. In case of MME overloading, the MME may reject therequest, otherwise, the MME may confirm (accept) the request, at step (3a).

As illustrated, at step (3 b), the MME may encapsulate the data in a NASPDU and prepare a paging message with the NAS PDU and send the pagingmessage to the eNB. In some cases, the MME may also include anindication of whether the message has to be acknowledged or not. The MMEmay also start a timer for retransmissions.

As illustrated at step (B), upon reception of the paging message, theeNB may prepare for the transmission and monitor for an ACK response.This process may be as follows: the eNB may determine an NPRACH resourcefor contention-free random access and include the corresponding resourceindex in the RRC paging message to the UE. The acknowledgement resourceallocation may only be done if Acknowledgement is required from the eNB.

FIG. 12 illustrates example code for formation of a paging message, inaccordance with certain aspects of the present disclosure. Of course,the variable names and values shown are for illustrative purposes onlyand actual names and values may vary.

Returning to FIG. 11 , as illustrated at step (4), the UE may monitorfor paging. This paging may be a regular type paging message or may bedifferent. For example, a different P-RNTI may be used for the UEmonitoring for small data enhancements. In such cases, the UE would needto monitor for two different P-RNTIs (one for normal paging message andone for modified paging message that contains NAS PDU).

At step (5), if the UE decodes paging (e.g., and it contains MT-data),then it does not go through the usual random access procedure/servicerequest. Instead, the UE may i) deliver the PDU to NAS and ii) transmitan (N)PRACH in the indicated resources (to acknowledge receipt of thedata). In such a case, the timing for this NPRACH transmission may bemore relaxed, since RRC has to process the PDU and go back to the PHY.For example, the first resource after N+20 may be used for NPRACHtransmission. In some cases (e.g., for extra security), the NPRACHresources can be transmitted inside the NAS PDU (and also scrambled withthe scrambling sequence), such that an eavesdropper cannot “ACK” thereception by a different UE. For example, this resource may also includea scrambling sequence/cyclic shift.

At step (6), upon detection of (N)PRACH, the eNB sends an ACK to theMME. In response, the MME may flush the data and stops a counter. If theMME does not receive an ACK, it may try to retransmit the data. Forexample, the MME may try to deliver again with small data over paging inmultiple eNB or the MME may try again using normal paging (e.g., andtransmit data in msg6 as per legacy procedures).

In some cases, the use of small data delivery as described herein maywarrant change in certain procedures, such as cell reselection, sincethe overhead due to “wrong eNB” when paging is high, since we aretransmitting the data directly in the paging message. In other words, itmay make sense to change the cell reselection algorithm to account forthe mismatch. For example, if the UE has announced that it is able toreceive NAS PDU over paging channel, it may change (or be configured tochange) the cell reselection algorithm (e.g. give higher priority to thecell in which the UE received the PDU). This may be implemented, forexample by adding an offset when ranking the cells to the cell in whichthe UE has received the last NAS PDU. In this manner, the UE may adjustcell reselection to remain on the cell where it received the NAS PDU. Insome cases, there could be a timer associated with this (e.g., during Xmin, the UE keeps the threshold to bias towards last cell, after that itdoes normal cell reselection).

There may also be changes in the random access procedure (as analternative to or in addition to changes in cell reselection). Forexample, the selection of power for NPRACH transmission may be differentthan that of regular random access. In some cases, the UE may simplytransmit NPRACH without monitoring MSG2. Alternatively, the UE maymonitor for MSG2, and continue the random access procedure until MSG2 isreceived which may be considered an ACK. In other words, MSG2 istypically a grant for MSG3 but, in this case, there is no MSG3 totransmit so MSG2 may be redefined to be an ACK and not contain anygrant). In some cases, in an initial message exchange, the applicationlayer can tell the UE that it is not a mobile UE, and the UE may sendthis “property” to the MME.

FIGS. 13-15 are example call flow diagrams illustrating differentoptions for delivering a small amount of MT data following a pagingmessage, in accordance with certain aspects of the present disclosure.

As illustrated in FIG. 13 , most of the call flow may be similar to thatdescribed with reference to FIG. 11 but, rather than send the data in apaging message, at step 4, the paging message may simply have anindication of a small amount of data to follow.

There are different ways to enable this. For example, in some cases, theeNB may transmit information regarding the data transmission in thepaging message (e.g. an RNTI to use for monitoring PDCCH-PDSCHcontaining the NAS PDU). This approach may have a reduced overhead, butif the UE does not receive the paging, the resources may be wasted andthe UE may not have timing advance information. In any case, the UE maymonitor the for PDCCH scrambled with a given RNTI, the correspondingPDSCH may contain the NAS PDU.

In some cases, if the UE does not decode the PDSCH with NAS, it can keepmonitoring PDCCH for some time for retransmissions. If the UE receivesPDSCH with NAS, it can send PRACH (as an ACK) and go back to sleep. Thissame idea can be applied to multiple NAS PDUs (e.g. monitor RNTI+timer).

As illustrated in FIG. 14 , in some cases, the UE may perform arelatively simplified RA procedure, at step (5), after receiving thepage indicating the small data to follow. The UE may then, afterreceiving the data transmission at step (6), send an ACK (e.g., via aPUCCH or NPRACH), at step (7), which the eNB forwards to the MME, atstep (8).

As illustrated in FIG. 15 , in some cases, the eNB may include anindication of an NPRACH resource for contention-free access in thepaging message, and UE transmits NPRACH. In this case, the NPRACH mayprovide confirmation that the UE is in the cell and, so, may reduceoverhead (e.g., the data may not be sent if no NPRACH is received by thebase station), however the NPRACH does take reserved resources. In anycase, upon detection of NPRACH, the eNB can include the data in MSG2, atstep 6 b. In some cases, the MSG2 may use a different RNTI (instead ofRA-RNTI) to avoid excessive power consumption to other UEs (RNTI can beincluded in paging message). The MSG2 may be scheduled, for example, by(N/M)PDCCH. MSG2 may also include power control/TA information and maybe ACK′ d, for example, by a PUCCH (since, in this case, the UE may haveTA and power control information).

FIGS. 16 and 17 illustrate example code for formation of a pagingmessage and downlink data message, in accordance with certain aspects ofthe present disclosure. As with FIG. 12 , the variable names and valuesshown are for illustrative purposes only and actual names and values mayvary.

To transmit MO data, current UEs may need to wait until msg5 to transmitdata (in NAS PDU). In other words, current techniques may require the UEto establish an RRC connection first just to send a very small amount ofdata. Aspects of the present disclosure, however, provide forconnectionless transmission of MO data (over NAS) in earlier messages(e.g. message 1 or message 3).

FIG. 18 illustrates example operations 1800 that may be performed by auser equipment to help optimize delivery of small amount of mobileoriginated (MO) data, in accordance with certain aspects of the presentdisclosure.

Operations 1800 begin, at 1802, by determining a set of resources forconnectionless delivery of a limited amount of data to a base station,based at least in part on an amount of the date the UE has to send. At1804, the UE transmits to the base station, while not in a connectedstate, the limited amount of data using the determined set of resources.

FIG. 19 illustrates example operations 1900 that may be performed by abase station to help optimize delivery of small amount of MO data, inaccordance with certain aspects of the present disclosure. For example,operations 1900 may be performed by a base station to receive a smallamount of MO data delivered by a UE performing operations 1800.

Operations 1900 begin, at 1902, by determining a set of resources forconnectionless delivery of a limited amount of data from a userequipment (UE) based at least in part on an amount of the date the UEhas to send. At 1904, the base station receives from the UE, while theUE is not in a connected state, the limited amount of data using thedetermined set of resources.

For transmission in message 1, the UE may not have uplink timing, so anew waveform or new procedures may be used. In some cases, a newwaveform may be used that is amenable to (1) Contention based and (2)Unsynchronized transmission. In some cases, an (N)PUSCH may be used, butthe UE may need to remember the TA from the last connection, such thatit remains orthogonal to other users.

In some cases, the eNB may reserve a set of resources for the MO datatransfer. If msg1 is to be used, the set of resources reserved may bedifferent for different coverage levels and/or packet sizes. If MSG3 isto be used, MSG1 resources may be partitioned according to different CElevels and/or coverage levels and/or packet sizes. In MSG2 (randomaccess response), the eNB may include the uplink grant, while MSG3 maycontain the data transmission, which may be encapsulated in a NAS PDU.Acknowledgement or contention resolution may be transmitted in a controlchannel or data channel (e.g. using RA-RNTI) and may include the UEidentifier (UE_ID) of UE that made it through.

FIG. 20 illustrates an example call flow diagram for optimized MO datadelivery in msg3. At step A), for resource allocation, the eNB decides,for example, to allow transmission of 10 bytes and 20 bytes without RRCconnection. It may, thus, give NPRACH resources for each size (and maybealso for different CE levels). At step 1), the eNB announces theresources (e.g., via SI). At step 2), the UE selects the resources basedon the announcement and the amount of data to transmit, and transmitsNPRACH. At step 3), the UE receives RAR which may include the uplinkgrant, power control and TA for MSG3. At step 4), the UE then transmitsMSG3 with UEID+NAS PDU. At step B), the eNB decodes the RRC message. Atstep 5 a), the eNB forwards the NAS PDU to the MME. At 5 b, the eNBsends the contention resolution (e.g. MPDCCH/PDCCH/NPDCCH or PDSCH withUEID) as an acknowledgement. If the UE does not receive the contentionresolution (ACK), it can retransmit the data again by restarting theprocedure.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover a, b, c,a-b, a-c, b-c, and a-b-c, as well as any combination with multiples ofthe same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b,b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. All structural andfunctional equivalents to the elements of the various aspects describedthroughout this disclosure that are known or later come to be known tothose of ordinary skill in the art are expressly incorporated herein byreference and are intended to be encompassed by the claims. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed under the provisions of 35U.S.C. § 112, sixth paragraph, unless the element is expressly recitedusing the phrase “means for” or, in the case of a method claim, theelement is recited using the phrase “step for.”

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.The means may include various hardware and/or software component(s)and/or module(s), including, but not limited to a circuit, anapplication specific integrated circuit (ASIC), or processor. Generally,where there are operations illustrated in figures, those operations mayhave corresponding counterpart means-plus-function components withsimilar numbering.

For example, means for transmitting and/or means for receiving maycomprise one or more of a transmit processor 420, a TX MIMO processor430, a receive processor 438, or antenna(s) 434 of the base station 110and/or the transmit processor 464, a TX MIMO processor 466, a receiveprocessor 458, or antenna(s) 452 of the user equipment 120.Additionally, means for generating, means for multiplexing, and/or meansfor applying may comprise one or more processors, such as thecontroller/processor 440 of the base station 110 and/or thecontroller/processor 480 of the user equipment 120.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device (PLD),discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

If implemented in hardware, an example hardware configuration maycomprise a processing system in a wireless node. The processing systemmay be implemented with a bus architecture. The bus may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system and the overall design constraints.The bus may link together various circuits including a processor,machine-readable media, and a bus interface. The bus interface may beused to connect a network adapter, among other things, to the processingsystem via the bus. The network adapter may be used to implement thesignal processing functions of the PHY layer. In the case of a userterminal 120 (see FIG. 1 ), a user interface (e.g., keypad, display,mouse, joystick, etc.) may also be connected to the bus. The bus mayalso link various other circuits such as timing sources, peripherals,voltage regulators, power management circuits, and the like, which arewell known in the art, and therefore, will not be described any further.The processor may be implemented with one or more general-purpose and/orspecial-purpose processors. Examples include microprocessors,microcontrollers, DSP processors, and other circuitry that can executesoftware. Those skilled in the art will recognize how best to implementthe described functionality for the processing system depending on theparticular application and the overall design constraints imposed on theoverall system.

If implemented in software, the functions may be stored or transmittedover as one or more instructions or code on a computer readable medium.Software shall be construed broadly to mean instructions, data, or anycombination thereof, whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise.Computer-readable media include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. The processor may beresponsible for managing the bus and general processing, including theexecution of software modules stored on the machine-readable storagemedia. A computer-readable storage medium may be coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium may beintegral to the processor. By way of example, the machine-readable mediamay include a transmission line, a carrier wave modulated by data,and/or a computer readable storage medium with instructions storedthereon separate from the wireless node, all of which may be accessed bythe processor through the bus interface. Alternatively, or in addition,the machine-readable media, or any portion thereof, may be integratedinto the processor, such as the case may be with cache and/or generalregister files. Examples of machine-readable storage media may include,by way of example, RAM (Random Access Memory), flash memory, ROM (ReadOnly Memory), PROM (Programmable Read-Only Memory), EPROM (ErasableProgrammable Read-Only Memory), EEPROM (Electrically ErasableProgrammable Read-Only Memory), registers, magnetic disks, opticaldisks, hard drives, or any other suitable storage medium, or anycombination thereof. The machine-readable media may be embodied in acomputer-program product.

A software module may comprise a single instruction, or manyinstructions, and may be distributed over several different codesegments, among different programs, and across multiple storage media.The computer-readable media may comprise a number of software modules.The software modules include instructions that, when executed by anapparatus such as a processor, cause the processing system to performvarious functions. The software modules may include a transmissionmodule and a receiving module. Each software module may reside in asingle storage device or be distributed across multiple storage devices.By way of example, a software module may be loaded into RAM from a harddrive when a triggering event occurs. During execution of the softwaremodule, the processor may load some of the instructions into cache toincrease access speed. One or more cache lines may then be loaded into ageneral register file for execution by the processor. When referring tothe functionality of a software module below, it will be understood thatsuch functionality is implemented by the processor when executinginstructions from that software module.

Also, any connection is properly termed a computer-readable medium. Forexample, if the software is transmitted from a website, server, or otherremote source using a coaxial cable, fiber optic cable, twisted pair,digital subscriber line (DSL), or wireless technologies such as infrared(IR), radio, and microwave, then the coaxial cable, fiber optic cable,twisted pair, DSL, or wireless technologies such as infrared, radio, andmicrowave are included in the definition of medium. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Thus, in some aspects computer-readable media maycomprise non-transitory computer-readable media (e.g., tangible media).In addition, for other aspects computer-readable media may comprisetransitory computer-readable media (e.g., a signal). Combinations of theabove should also be included within the scope of computer-readablemedia.

Thus, certain aspects may comprise a computer program product forperforming the operations presented herein. For example, such a computerprogram product may comprise a computer-readable medium havinginstructions stored (and/or encoded) thereon, the instructions beingexecutable by one or more processors to perform the operations describedherein. For example, instructions for perform the operations describedherein and illustrated in FIGS. 13, 17, and 18 .

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a user terminal and/or basestation as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a userterminal and/or base station can obtain the various methods uponcoupling or providing the storage means to the device. Moreover, anyother suitable technique for providing the methods and techniquesdescribed herein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

1. An apparatus for wireless communication, comprising: a firstinterface configured to output for transmission system informationindicating different sets of resources allocated to different coveragelevels; at least one processor configured to determine a set ofresources from the different sets of resources based at least in part onan amount of mobile originated (MO) data a user equipment (UE) has tosend; and a second interface configured to obtain a physical randomaccess channel (PRACH) transmitted by the UE, wherein: the firstinterface is further configured to output for transmission a randomaccess response (RAR) message after the PRACH was obtained, and thesecond interface is further configured to: obtain, after the RAR messagewas output for transmission and independent of a radio resource control(RRC) connection with the UE, a non-access stratum protocol data unit(NAS PDU) from the UE, wherein the NAS PDU includes the amount of MOdata encapsulated as the NAS PDU.
 2. The apparatus of claim 1, whereinthe RAR message includes at least one of an uplink grant, a powercontrol command, or a timing advance (TA) to be used by the UE fortransmitting the amount of MO data.
 3. The apparatus of claim 1, whereinthe NAS PDU comprises a request including a UE identifier.
 4. Theapparatus of claim 3, wherein the first interface is further configuredto output for transmission a contention resolution message containingthe UE identifier as an acknowledgement of receipt of the amount of MOdata.
 5. The apparatus of claim 1, wherein the second interface isfurther configured to obtain the PRACH independent of the UE being in aconnected state.
 6. The apparatus of claim 1, further comprising: atleast one transceiver configured to: transmit the system information;transmit the RAR message; receive the PRACH; and receive the NAS PDU;and wherein the apparatus is configured as a network entity.
 7. Anapparatus for wireless communication, comprising: means for transmittingsystem information indicating different sets of resources allocated todifferent coverage levels; means for determining a set of resources fromthe different sets of resources based at least in part on an amount ofmobile originated (MO) data a user equipment (UE) has to send; means forreceiving, from the UE, a physical random access channel (PRACH); meansfor transmitting a random access response (RAR) message after receptionof the PRACH; and means for receiving, after the RAR message wastransmitted and independent of a radio resource control (RRC) connectionwith the UE, a non-access stratum protocol data unit (NAS PDU) from theUE, wherein the NAS PDU includes the amount of MO data encapsulated asthe NAS PDU.
 8. The apparatus of claim 7, wherein the RAR messageincludes at least one of an uplink grant, a power control command, or atiming advance (TA) to be used by the UE for transmitting the amount ofMO data.
 9. The apparatus of claim 7, wherein the NAS PDU comprises arequest including a UE identifier.
 10. The apparatus of claim 9, furthercomprising means for transmitting a contention resolution messagecontaining the UE identifier as an acknowledgement of receipt of theamount of MO data.
 11. The apparatus of claim 7, wherein the means forreceiving the PRACH comprises means for receiving the PRACH independentof the UE being in a connected state.
 12. A method for wirelesscommunication, comprising: transmitting system information indicatingdifferent sets of resources allocated to different coverage levels;determining a set of resources from the different sets of resourcesbased at least in part on an amount of mobile originated (MO) data auser equipment (UE) has to send; receiving, from the UE, a physicalrandom access channel (PRACH); transmitting a random access response(RAR) message after receiving the PRACH; and receiving, aftertransmitting the RAR message and without establishing a radio resourcecontrol (RRC) connection with the UE, a non-access stratum protocol dataunit (NAS PDU) from the UE, wherein the NAS PDU includes the amount ofMO data encapsulated as the NAS PDU.
 13. The method of claim 12, whereinthe RAR message includes at least one of an uplink grant, a powercontrol command, or a timing advance (TA) to be used by the UE fortransmitting the amount of MO data.
 14. The method of claim 12, whereinthe NAS PDU comprises a request including a UE identifier.
 15. Themethod of claim 14, wherein the method further comprises transmitting acontention resolution message containing the UE identifier as anacknowledgement of receipt of the amount of MO data.
 16. The method ofclaim 12, wherein receiving the PRACH comprises receiving the PRACHwhile the UE is not in a connected state.